For the cheese sauce, in a medium saucepot over medium-high heat, melt margarine. Add flour and whisk together. Reduce heat to medium and brown mixture for 1 to 2 minutes. Whisk in soymilk. Once soymilk comes to a boil, stir in cheese and nutritional yeast and continue to stir constantly. Once cheese is melted, remove from heat and set aside.

To assemble the nachos, make a bed of tortilla chips, cover with warm quinoa filling, and top with cheese sauce, scallions, olives, and salsa. Serve hot.